⇒ The standard Avoirdupois pound of the United States is equivalent to the weight of 27.7015 cubic inches of distilled water at 62° Fahrenheit, the barometer being at 30 inches, and the water weighed in the air with brass weights. In this system of weights 16 drams make 1 ounce, 16 ounces 1 pound, 25 pounds 1 quarter, 4 quarters 1 hundred weight, and 20 hundred weight 1 ton. The above pound contains 7,000 grains, or 453.54 grams, so that 1 pound avoirdupois is equivalent to 1 31-144 pounds troy. (See Troy weight.) Formerly, a hundred weight was reckoned at 112 pounds, the ton being 2,240 pounds (sometimes called a long ton).